Rust inhibited fuels



2,929,696 RUST INHIBITED FUELS Maurice R. Barusch, Richmond, and Beppino J. Fontana,

Berkeley, Calif., assignors to California Research Corporation, San Francisco, Calif., a corporation of Delaware Application September 6, 1957 Serial No. 682,321

6 Claims. (CI. 44-46 No Drawing.

from ferrous metals. Variation in temperature results in air being drawn into the storage vessel, with subsequent condensation of liquid water. Liquid water is also introduced during manufacturing processes, such as sweetening. Thus, the storage vessels which, as noted hereinabove, are commonly of ferrous metals, rust. The

rusting is sufiicient in the storage and piping equipment ",2 exemplified by the following radicals:

to result in the formation of large rustparticleswhich flake from the metal surfaces. Not only is'the life of the storage vessel and the piping equipment reduced by such rusting process, but the. resulting rust particles often aired StatesPatenrC preparation, motor fuelcomposibecome carried into the fuel tanks of the service stations which serve the ultimate consumer. The rust par- 'ticles may find their way into the gasoline tank ofan automobile or the fuel tank of a diesel powered truck, causing plugging of fuel lines and filters. Also, this rusting and flaking in pipe lines causes the inner pipe surfaces to become irregular and rough, increasing the friction between the flowing fuel and the pipe. This increase in friction reduces the'volunie of fuel which'can flow through the pipe lines.

The petroleum industry hasbeen trying to find a solution to this problem fora great many years, and'itis well known that many dillerent types of procedures-have been used in attempts to eliminate this rusting problem.

Therefore, it is an object of this invention to provide V 7 containers for motor fuels is appreciably reduced in the presence of water and of oxygen.

In accordance with this invention, it has been discovered that rust inhibited motor fuel compositions are obtained by incorporating oleic acid and polyglycols therein. Thus, the motor fuel compositions of this invention comprise a majorproportion of a hydrcarbon (or mixture of hydrocarbons) suitable as a fuel for internal combustion engines, and a minor amount, sufiicient to inhibit rusting of said fuel in the presenceof water and oxygen, of the combination of oleic acid and a polyglycol.

The base fuels are hydrocarbon distillates (e.g., petroleum distillates) such as gasolines, diesel fuels, and jet fuels currently produced for commercial use from petroleum stocks. Such base fuels may be derived from cracked or straight-run stocks or a blend of such stocks, and include the hydrocarbons derived from shales and motor-fuel compositions useful ininterna] combustion 2,929,696 Patented Mar. 22, 1960 wherein R is hydrogen ora hydrocarbon radical having less than 19 carbon atoms, at and y are numbers from0 to. .about 200. 'Preferred are polymers containingatotal ofabout 6 to. about 9.0 alkyleneoxide units. Moreparticularl'y preferred are the .polymers containing a: total of about l4 to 25. alkylene oxide units, made u of about an equal molar ratio of ethylene oxide and propylene oxide units, and wherein R in the above formula is a butyl radical. Thus, it is preferred that the sum of x and y be from about 14 to about 25,,with the mo] ratio of ethylene oxide and propylene oxide beingabout 1:].

Where R is. not hydrogen, it is an aliphatic hydrocarbon radical :containing no more than 18 carbon atoms, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, n-octyl, isooctyl, Z-ethylhexyl, nonyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc.

As is seen 'from the -formula hereinabove for the polyglycols used herein in combination witholeic acid, the polyglycols may be derived, from ethylene oxide, propylene oxide or a combination of ethylene, andpropylene oxides. The polyglycols which are elfective herein are those having molecular weights ranging from about 300 to about 10,000. However, because ofthe greater elfectiveness thereof, it is preferred that the molecular weights range from about 500 to about 4000.

The weight ratio of oleic acid 'to polyglycol employed in.the fuel composition is from about 50:1 to about 2:1.

Preferred are ratios from about 25:1 to about 5:1. The

concentration of the combination added to the fuel may vary from about 5 p.p.m. to about 250 ppm. The preferred concentration of the combination of oleic acid and polyglycol varies from about 10 ppm. to p.p.m.

Table I hereinbelowp'resents data showing the eifectiveness of the -combination 'ofoleic'acid and polyalkylene glycols as rust inhibitors in motor fuel compositions.

The rust ratings were obtained by the ASTM procedure D-665 modified to a test duration of 20 hours and carried out at F. In this test, the test metal specimen was immersed in kerosene, which served as the base fuel. Synthetic sea water was used. The resultant specimens were visually rated as to the amount of corrosion. A rating of 7 means that the panel was fully rusted and rating of 1 indicates ,no rust on the panel.

The kerosene used had a distillation range (i.e., a boiling range) from about 340 F. to 540 F. In each instance the kerosene contained 20 p.p.m. of oleic acid plus 2 p.p.m. of the noted polyglycol.

In the test wherein kerosene alone (without any additive) was used, the test panel became completely covered with rust for a rating of 7; and the kerosene composition containing 20 ppm. of oleic acid gave a test rating of 5.

Table I Polyalkylene Oxide Chain Test No. R" Radical Rust Rating 1: 1,! Molecular Weight Table II hereinbelow shows the effect obtained on the rust inhibition by varying the amount of oleic acid with respect to the polyglycol. This test was run in the same manner as the one described hereinabove for Table I.

The polyglycol used in this test was the polyglycol described in test No. 6 of Table I hereinabove.

The use of the combination of oleic acid and polyglycols as rust inhibitors in gasolines can be further exemplified by incorporating the combination of 20 p.p.m. of oleic acid and 2 p.p.m. of the polyglycol described in Test No. 6 of Table I, hereinabove, in a gasoline having a distillation range (i.e., a boiling range) from about 100 F. to about 400 F,

We claim:

1. A rust inhibited fuel compositionconsisting essentially of an internal combustion engine liquid hydrocarbon fuel having incorporated therein from p.p.m. to 75 p.p.m. of the combination of oleic acid and a polyglycol of the formula I 7 CH:

nowmcmonwmcnonn g esses wherein R represents an octade cyl radical, and x plus y has a value from about 14 to about 25, and wherein the weight ratio of oleic acid to said polyglycol has a value from 25:1 to 5:1.

2. A rust inhibited fuel composition consisting essentially of an internal combustion engine liquid hydrocarbon fuel having incorporated therein from 10 p.p.m. to p.p.m. of the combination of oleic acid and a polyglycol of the formula l notoigicmomenacno n wherein R represents a lauryl radical, and x plus y has a value from about 14 to about 25, and wherein the weight ratioof oleic acid to said polyyglycol has a value from25:1to5:l.

.4. A rust inhibited fuel composition consisting essentially of a major proportion of a gasoline having incorporated therein from 5 p.p.m. to about 250 p.p.m. of the combination of oleic' acid and a polyglycol of the or la nowmonionwnzbnonn wherein R is an aliphatic radical having no more than 18 carbon atoms, x and y are numbers having a total value ranging from about 14 to about 25 and wherein the weight ratio of oleic acid to said polyglycol is from about 25 :1 to about 5:1.

5. The composition of claim 4, wherein R is a butyl radical. 1

6. The composition of claim 4, wherein R is a lauryl radical;

References Cited in the file of this patent UNITED STATES PATENTS 

1. A RUST INHIBITED FUEL COMPOSITION CONSISTING ESSENTIALLY OF AN INTERNAL COMBUSTION ENGINE LIQUID HYDROCARBON FUEL HAVING INCORPORATED THEREIN FROM 10 P.P.M. TO 75 P.P.M. OF THE COMBINATION OF OLEIC ACID AND A POLYGLYCOL OF THE FORMULA 